Directional orientation of reconstituted lignocellulosic materials is known in the prior art as, for example, disclosed in U.S. Pat. Nos. 4,113,812 and 4,111,294. These patents discloses electrostatic orientation of lignocellulosic fibrous material in the direction of movement of a mat being formed on a moving horizontal support surface, or caul belt.
U.S. patent application Ser. No. 106,686, filed on Dec. 26, 1979, now U.S. Pat. No. 4,287,140, assigned to the same assignee as this application, discloses a continuous method and apparatus for forming an electrostatically oriented mat of discrete particles of lignocellulosic material making use of a transfer surface to transfer a mat of directionally aligned particles to a caul plate. An electrically non-conductive transfer surface is employed for formation of the mat thereupon, which mat is then transferred, with the particles oriented in the direction of movement of the mat being formed, onto a grounded, moving, electrically conductive, mat-receiving surface while still under the influence of an electrostatic field so that the particles do not lose their orientation. The structure disclosed includes multiple electrostatic plates aligned transversely to the direction of movement of the mats being formed. Particles free-fall through the electric field formed between the plates and are aligned along the direction of movement of the mat.
Formation of a mat having particles electrically aligned in the cross-machine or transverse direction to the direction of movement of the mat has not been satisfactorily carried out commercially.